Push sigma-based blur interface into our GMs/benches/tests/samplecode

gm/blurquickreject.cpp

Index: gm/blurquickreject.cpp
===================================================================
--- gm/blurquickreject.cpp	(revision 11004)
+++ gm/blurquickreject.cpp	(working copy)
@@ -30,15 +30,15 @@
     }
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
-        static const SkScalar kBlurRadius = SkIntToScalar(20);
+        static const SkScalar kSigma = SkFloatToScalar(12.047f); 
         static const SkScalar kBoxSize = SkIntToScalar(100);
 
         SkRect clipRect = SkRect::MakeXYWH(0, 0, kBoxSize, kBoxSize);
         SkRect blurRects[] = {
-            { -kBoxSize - (kBlurRadius+1), 0, -(kBlurRadius+1), kBoxSize },
-            { 0, -kBoxSize - (kBlurRadius+1), kBoxSize, -(kBlurRadius+1) },
-            { kBoxSize+kBlurRadius+1, 0, 2*kBoxSize+kBlurRadius+1, kBoxSize },
-            { 0, kBoxSize+kBlurRadius+1, kBoxSize, 2*kBoxSize+kBlurRadius+1 }
+            { -kBoxSize - kSigma, 0, -kSigma, kBoxSize },
+            { 0, -kBoxSize - kSigma, kBoxSize, -kSigma },
+            { kBoxSize+kSigma, 0, 2*kBoxSize+kSigma, kBoxSize },
+            { 0, kBoxSize+kSigma, kBoxSize, 2*kBoxSize+kSigma }
         };
         SkColor colors[] = {
             SK_ColorRED,
@@ -55,8 +55,8 @@
 
         SkPaint blurPaint;
         blurPaint.setFilterBitmap(true);
-        SkMaskFilter* mf = SkBlurMaskFilter::Create(kBlurRadius,
-                                                    SkBlurMaskFilter::kNormal_BlurStyle);
+        SkMaskFilter* mf = SkBlurMaskFilter::Create(SkBlurMaskFilter::kNormal_BlurStyle,
+                                                    kSigma);
         blurPaint.setMaskFilter(mf)->unref();
 
         canvas->clear(SK_ColorBLACK);